To find the missing values, we begin by breaking down the expression 8(2r + 8) using the property of distribution in multiplication. This can be done by multiplying 8 by each term in the brackets. Here are the step-by-step calculations:
1) First, multiply 8 by 2r (which represents length_B1). The result, denoted here as B1, is 16.
2) Next, multiply 8 by 8 (which represents length_B2). The result, denoted here as B2, is 64.
Therefore, the values of B1 and B2 are 16 and 64 respectively. These represent the area of two rectangular regions.
3) To find the total area represented by the expression 8(2r + 8), we add the areas of our two regions (B1 and B2). Therefore, the total area is B1 + B2, which is 16 + 64 = 80.
So, the missing values for the area model of the expression 8(2r + 8) are B1 = 16, B2 = 64, and the total area equals 80.